Infection in a major cause of serious morbidity and the major cause of death at this Center. Patients with acute leukemia tend to become infected with hospital-acquired organisms such as Pseudomonas aeruginosa; those with mycosis fungoides are susceptible to Staphylococcus aureus acquisition and infection, and patients with lymphoma are prone to develop Herpes zoster. Various programs have been assigned to evaluate methods for reducing infectious complications among these patients with the intent of improving the quality of survival and increasing the chance for complete tumor remission. These include basic infection prevention measures, use of laminar air flow rooms plus oral nonabsorbable antibiotics, specific prevention of staphylococcal infections, and use of Zoster immune plasma.